Fluid filled submersible motor



Sept. 4, 1962 P. s. KOMOR FLUID FILLED SUBMERSIBLE MOTOR Filed July 6,1959 INVENTOR. Psree 5o Kan/x0e & I M

flrroe vsys- United States Patent 3,052,804 FLUID FILLED SUBMERSIBLEMOTOR Peter Sandor Komor, Los Angeles, Calif., assignor to U. S.Electrical Motors, Inc., a corporation of California Filed July 6, 1959,Ser. No. 825,353 2 Claims. (Cl. 310--87) This invention relates tosubmersible electric motors, adapted to be submerged in a well and tooperate a pump or the like. In many of these motors, a fluid is used tofill the motor casing and to keep the windings from contact with thesurrounding water.

The pressure of the fluid in the casing when the motor is installed ismaintained at or a little greater than the liquid pressure of the waterexterior of the casing, by the aid of a movable wall or diaphragm in amanner now understood.

The casing is filled with fluid prior to shipment of the motor. Duringshipment it is desirable to prevent the entry of air into the casing toreplace fluid, such as oil, that may leak out. This is usuallyaccomplished by providing a spring that exerts a force on the diaphragmto keep the internal pressure continuously slightly above the airpressure so that a small amount of fluid is continuously exuded duringthe period of shipment and storage and, to lesser extent, after themotor is installed.

It is one of the objects of this invention to improve, in general,submersible motors of this character; and particularly by making itpossible to reduce the loss of fluid after the motor is in operation.

This invention possesses many other advantages, and has other objectswhich may be made more clearly apparent from a consideration of oneembodiment of the invention. For this purpose, there is shown a form inthe drawings accompanying and forming part of the present specification.This form will now be described in detail, illustrating the generalprinciples of the invention; but it is to be understood that thisdetailed description is not to be taken in a limiting sense, since thescope of this invention is best defined by the appended claims.

Referring to the drawings:

FIGURE 1 is a view, mainly in longitudinal section, of a submersiblemotor incorporating the invention, the motor elements being showndiagrammatically;

FIG. 2 is a fragmentary view illustrating a stage in the loss of liquidin the casing after the motor is installed; and

FIG. 3 is a view, similar to FIG. 2, illustrating a further stage in theloss of liquid.

In FIG. 1 a submersible electric motor 1 is shown having an upper casing2 in which is mounted a motor stator and rotor and a lower casing orhousing 2a. The lower casing 2a is open at its bottom, but it isintended to be sealed by the aid of a flexible wall or bag-likecontainer 3 having a conical flange 4. This flexible wall may be ofrubber or rubber-like material. It is held in place against the bottomof the lower casing 2a by the aid of a cover 5. The cover 5 and thelower casing 2a have cooperating flanges 6 and 7 appropriately attachedtogether, and between which flanges the edge of the flange 4 is clamped.

The motor 1 is provided with an upwardly extending vertical shaft 8adapted to drive a load, such as a pump or the like.

Before the motor 1 is installed in a well, both the casing sections 2and 2a are filled with a fluid 11. Sulficient pressure is exerted duringthe filling operation to ensure that the fluid pressure urges the endportion of the wall 3 downwardly against the force of a compressionspring 9 arranged in the bottom or seat portion of cover 5. In orderthat there be no danger during shipment or storice age that any air mayenter the casing 2-2a and thereby cause injury, as by rust or corrosion,the compression spring 9 is utilized. It rests on the bottom of thecover 5. This compression spring is seated in a spring seat 10 attachedto the upper turn of the spring 9. The spring exerts a pressure on wall3 so that the fluid pressure within the casing 2-2a is always a littlegreater than the atmospheric pressure.

In normal shipment, therefore, as the spring 9 gradually expands, asmall amount of fluid is exuded from the submersible motor. Thiscontinues for an appreciable period, sutficient :to correspond at leastto the period of storage and shipment to the place of use.

The wall 3 is so arranged that it can be reversed or turned inside outto the position shown in FIG. 3, leaving a minimum volume for the fluid11. Thus, when the motor '1 is installed in a well, the pressure of thewell water urges the wall 3 upwardly and prevents ingress of well waterinto the casing 2-2a.

The spring 9 is purposely so proportioned that it is eflective toprovide a compressive force upon the fluid filling 11 only duringshipment, at which time the spring 9 remains in constant contact withwall 3. FIG. 2 illustrates the free position of spring 9 after the motoris installed, and the wall 3 and its flange 4 are being turned insideout by the loss of fluid in the well. Since the internal and externalpressures are almost completely balanced, the position of wall 3 changesvery gradually.

In order to permit well water to reach the outer surface of the wall 3,a port 12 is provided in the bottom of the cover 5. By the provision ofshort spring, greater volume is secured for the fluid 1-1 within themotor casing for the same overall length of the motor 1.

The inventor claims:

1. A submersible motor structure comprising a motor stator and rotor, acasing for said stator and rotor having a top section and a bottomsection, a flexible extendible and collapsible bag-like containeraffixed to said bottom section, the interior of said flexible containerbeing in communication with the interior of said casing, said containerhaving an end portion, a compression spring, a seat means for saidspring supported by said casing and positioned in opposed relation tosaid end portion of said container outside said container, said springbeing interposed between said seat and said end portion, said endportion of said container having a traverse between a first positionwherein said container is in fully extended condition and a secondposition wherein said container is in fully collapsed condition, saidspring being compressed between said seat and end portion of saidcontainer when said end portion is in said first position, said springhaving a length when fully relieved of compression of only a portion ofthe length of said traverse of said end portion of said containerbetween said first and second positions, and a fluid filling said casingand container, whereby when the motor is in use submersed in a liquidmedium with said top section located above said bottom section, thepressure of the surrounding medium continues to exert a net collapsingforce on said container after said spring is fully relieved ofcompression.

2. A submersible motor structure comprising a motor stator and rotor, acasing for said stator and rotor having a top section and a bottomsection, a flexible extendible and collapsible bag-like containeraflixed to said bottom section, the interior of said flexible containerbeing in communication with the interior of said casing, said containerhaving an end portion, a compression spring, a housing for said springand container supported by said casing including a seat portion for saidspring positioned in opposed relation to said end portion of saidcontainer, said spring being interposed between said seat and said endportion, said end portion of said container having a traa versehetween afirst position wherein said container is in fully extended condition anda second position wherein said container is in fully collapsedcondition, said spring being compressed between said seat and endportion of said containerw'hen said end portion is in said firstposition, said spring 'having a relaxation traverse from said compressedstate to a maximum elongation in said housing which is only a portion ofthe length of said traverse of said end portion of 'said containerbetween said first and second ,positions, .and la .fiuid filling saidcasing and con- 4. tainer, whereby when the motor is in use submersed ina liquid medium With-said top section located above said 'bottomsection, the pressure of the surrounding medium continues to exert a netcollapsing force on said container 5 after said spring has reached saidmaximum elongation.

References Cited in the file of this patent UNITED STATES PATENTSPatterson et al Mar. 20, 1956 Dochterman Apr. 3, 1956

